Many modern vehicles utilize antenna systems to transmit and/or receive radio waves, for example, for wireless communications and/or radar. Typically, an antenna is installed on an exterior of the vehicle. Many antenna systems that utilize an exterior-mounted antenna also include a radome or other enclosure that covers the radiating element of the antenna and protects the antenna from exposure to the environment. Many antenna systems also include a cavity structure that defines a resonance cavity located behind the radiating element of the antenna. The cavity enforces unidirectional radiation from the antenna. Among other factors, the dimensions of the cavity and, thus, the size of the antenna primarily depend on the operating frequency of the antenna.
In certain applications, such as in aerospace and electronic, the size of the antenna cavity is a significant design constraint. One solution to reduce the size of the cavity is to fill the cavity with a dielectric loading mechanism, also referred to as loading the cavity. However, this reduction in size typically comes at the expense of increased weight, which is another significant design constraint in many applications.
Accordingly, those skilled in the art continue with research and development efforts in the field of cavity-backed antennas.